Piano Caster Cups - Can hold and support your piano securely for years of use. Also works for wheelchair leg protectors and bed leg floor protectors.Floor Protectors - Designed for piano legs, these piano casters should be placed under the legs of a piano to protect hardwood, wood, tile and carpet.Anti-Corrosion - Piano casters protect the piano's metal and brass wheels from rusting or tarnishing. Set includes 4 piano coasters.Long Use Time - Pads designed to protect your hardwood floors, carpets and rugs. Will not tear or distort the surface under the weight of the piano while maintaining proper pedal height.Features:Designed to be placed under piano feet to protect floors and carpets.Advanced durable plastic design.Designed for use with pianos.Protects wood, tile and carpet from damage caused by piano casters.Color: Black.Outer diameter: 88mm.Inner diameter: 53mm.Package includes:4 x piano casters pads Note: The data are all manual measurements, please allow 1-3cm error, due to the